Aluminum alloy



' To all whom it may concern.

' ninum alloys.

UNITED STATES PATENT OFFICE.

HORACE CAMPBELL HALL, OF DERBY, ENGLAND, ASSIGNOR T0, ROLLS-ROYCE LIMITED,

OF DERBY, ENGLAND, A COMPANY OF GREAT BRITAIN.

' ELU miUM ALLOY.

No Drawin g.

Be it known that I, HORACE CAMPBELL HALL, of Derby, England, have invented certain new and useful Improvements in Aluminum Alloys, of which the following is a specification. Y

This invention consists of improved aluan alloy is made consisting of Copper about .1% to any amount below Titanium about .1% to about 2%. Zinc about 6% to about 16%.

Iron (present as an impurity of commer-- cial aluminum) preferably not exceeding .6%.

Silicon (present as an impurity of commercial aluminum) preferably not exceed ing Other elements (impurities) preferably not exceeding 4%.

Aluminum remainder.

The alloy can be made as follows A coppertitanium aluminum alloy should be made in the first instance consisting of Copper about 32%.

Titanium about 7.5%.

Aluminum about 59%.

Other elements (impurities) preferably not exceeding 1.5%.

In the above the quantities of titanium and aluminum may be varied about 2% above or below the percentages stated. Further a slightly higher percentage of copper may be used dependent on the ultimate properties required;

The alloy so made is then introduced in the form of suitable sized pieces or granules into a bath of molten commercial aluminum in which it will readily dissolve. The zinc should then be added but it is preferable to retain a small proportion, say 1% thereof to be added later as hereinafter explained.

If it is desired to increase the ratio of copper to titanium it should be done by the addition of a copper aluminum alloy. to the ultimate bath simultaneously with the primary alloy.

The alloy is improved by the substitution for not exceeding 3% of the aluminum, of

antimony and/or magnesium not exceeding in respect of either about 1.5%.

If antimony or magnesium or both are required. these should preferably be. added to the final bath of metal together with' the According-to this invention Specification of Letters Patent. Patented June 6, 1922.

Application filed February 18, 1921. Serial No. 446,115.

small percentage of the zinc about 5 minutes before casting.

The introduction of the small quantity of zinc retained as aforesaid at the stage prescribed augments the clearing action of the antimony and magnesium and even by itself makes the metal more fluid.

Alloys made according to this invention of the composition specified above are found to give the following advantages over aluminum alloys heretofore in use 1. Increased fluidity in the molten icondition.

2. A reduced tendency to crack in the mould during solidification,

3. An absence of gas cavities, resulting in sounder and finer grained castings.

' 4. An improvement in mechanical test results, including a raising of the yield point,

and an increase in ductility.

5. A reduction in the co-efiicient of heatex ansion of the resulting alloy.

hat I claim as my invention and desire to secure. by Letters Patent of, the United States is 1. An alloy, comprising 1 to 3% copper;

I 1 to 2% titanium; 6 to 16% zinc; and impurities contained in commercial aluminum, r

not exceeding 1% in the aggregate; the remainder consisting mostly of aluminum. I

2. An alloy, comprising 1 to 3% copper; 1 to 2% titanium; 6 to 16% zinc; magnesium, not exceeding 1.5%; and impurities contained in commercial aluminum,-no t exceeding 01% in the aggregate the remainder 1 consisting mostly of aluminum.

3..An alloy comprising 1 to 3% copper 1 to 2% titanium; 6 to 16% zinc; magnesium, and antimony, not exceeding 1.5% of each; and lmpurities contained in commercial aluminum, not exceeding 1 in. the aggregate; the remainder consisting mostly I of aluminum. 7 I

4. The process of forming an alloy, comprising the steps of first forming a coppertitanium-aluminum alloy; introducing such alloyin particles of suitable size into a bath of molten commercial aluminum to be dissolved therein; and then adding'zinc to the resultant mixture.

5. The process of forming an alloy, comprising the steps of first forming a coppertitanium-aluminum alloy; introducing such alloy in particles of suitable size into a bath of molten commercial aluminum to be dis- Q 7 I i 1,418,303

solved therein; then adding zinc; and then adding magnesium and antimony to the re- 10 adding maganesium to the resultant mixsultant mixture.

ture. In Witness whereof I have signed this 6. The process of forming an alloy, comspecification in the presence of two Witprising the steps of first forming a coppernesses.

titanium-aluminum alloy; introducing such HORACE CAMPBELL HALL. alloy in particles of suitable size into a bath Witnesses: of molten commercial aluminum to be dis- NORMAN HAY WALKE solved therein; then adding zinc; and then VIOLET MAUD MASTERS. 

